Tomer B S, Harvold E P
Am J Orthod. 1982 Aug;82(2):114-9. doi: 10.1016/0002-9416(82)90490-0.
Induced oral respiration in eight growing monkeys led to a lowering of the chin, a steeper mandibular plane angle, and an increase in the gonial angle as compared with eight control animals. The posterior border of the mandible maintained its normal inclination relative to the skull. The mandible underwent a posterior rotation in the experimental animals and an anterior rotation in the controls. The findings suggest that the position of the chin and the inclination of the mandibular plane are controlled by the balance between the suprahyoid and the orofacial muscles. Since the posterior border of the ramus undergoes gradual remodeling and maintains its normal inclination, it is assumed that the masticatory muscles are not significantly affected by the altered respiratory function. It is therefore concluded that the ramus with the masticatory muscles and the chin with its suprahyoid and orofacial muscles represent two relatively independent systems.
与八只对照猴相比，八只生长中的猴子经诱导产生口呼吸后，出现了下巴降低、下颌平面角变陡以及下颌角增大的情况。下颌骨后缘相对于颅骨保持其正常倾斜度。实验动物的下颌骨发生了向后旋转，而对照动物的下颌骨发生了向前旋转。这些发现表明，下巴的位置和下颌平面的倾斜度由舌骨上肌群和口面部肌肉之间的平衡所控制。由于下颌升支后缘会逐渐重塑并保持其正常倾斜度，因此推测咀嚼肌并未受到呼吸功能改变的显著影响。由此得出结论，带有咀嚼肌的下颌升支和带有舌骨上肌群及口面部肌肉的下巴代表两个相对独立的系统。
